"To find the genetic basis of this quick adaptation, a team led by evolutionary biologist Mark Christie from Purdue University in West Lafayette, Indiana, and his postdoc Janna Willoughby sequenced the genomes of 264 steelhead. Some came from the source waters in California that supplied the first Lake Michigan fish, while others were collected from the lake’s watershed in 1983 and 1998. By comparing those genomes, they reconstructed the steelhead’s struggles to adapt.

The first batch of transplants had a hard time, likely dying off by the hundreds. But the few that survived thrived, and between 1983 and 1998, their population started to rebound and even diversify, most likely because of interbreeding with newly introduced hatchery fish, Willoughby and Christie report this week in Molecular Ecology."

[sciencemag.org]